Why there are so many different Visual C++ redistributables ?

If you are wondering, Why So Many Different Versions of Visual C++ Redistributables?

Visual C++ redistributables are components shipped by app developers who use Visual C++ to write their software. 
By using Microsoft’s well-tested and widely used code inside their apps, developers save their development cost by avoiding writing commonly-used code (e.g. sin and cos math functions and handling of common user interface elements like textbox or button).
Due to fragmentation in the runtime versions used by the app developers, you would see a long list of Visual C++ redistributables if you install a lot of apps.
Uninstalling one Visual C++ redistributable could save you a few megabytes of disk space, but you risk breaking some apps in doing so.
Because programmers rely on Microsoft to keep the Visual C++ runtime up to date. Microsoft releases the security updates for the redistributables, but due to developer demands, Visual C++ redistributables do not supersede each other and old versions are kept for compatibility.

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